i3 Rework Jhead Shroud for 50mm fan (40mm screw spacing)

I have no 40mm fan so I remaked http://www.thingiverse.com/thing:209423
My version has 40mm screw spacing, so it can hold 50mm fan now.
I also added decoration holes (it really has no purpose), removed mount support and repaired model manifold.

Added model with mount for http://www.thingiverse.com/thing:84836